Grease gun



Jan 6, 1931. c. F. GODDARD GREAS E GUN Filed March 26'. 1928 N V EN TOR.

Patented Jan. 6, 1931 GREASE GUN Application med larok 26, 1928. Serial No. 264,940.

My invention relates to lubricating devices of the type commonly known as grease guns, and its primary object is to provide apparatusof this` character in which a lubricant reservoir is demountably associated with a mechanism to forcibly feed lubricant from the reservoir to a machine part.`

By the use of my invention, containers previously filled with a lubricant, may be held in reserveLso thatgwhen one container is exhausted, another may be immediately ap lied in the place thereof.

nother object of the invention is to provide in a grease gun, a very simple means for ejecting the lubricant from the reservoir by means of compressed air or other pressure fluid.

A further object is to provide a gun course of the following description. v

ln the accompanying'drawings in which like characters .of reference designate corresponding parts throughout the views, Figure 1 represents a sectional elevation of a grease gun constructed in accordance with my invention, a portion thereof having been broken away for lack of space,

The stock is, at its forward end, enlarged A CHARLES F. GODDARD, 0F DENVER, COLORADO Russa-in to provide a cylindrical piston-chamber 8 which is closed by means of a head 9 that has an air vent 54. The head has, in coaxial relation with the piston chamber, a plungerchamber 10 of smaller diameter, which, by means of a duct 12, is connected with the interior of a coupling-member 13, adapted to connect the plunger-chamber with either the reservoir or a machine part to which the lgun is applied.

The coupling has, at one end of its interior passage, a packing gland 14, adapted to admit a nipple 15 on the reservoir, as will hereinafter e described, and the flow of lubricant through said passage between the nipple and the duct, is controlled by a checkvalve 16.

The valve is preferably of ball-form and is normally held in engagement with its seat 17 by a coiled spring that abuts against a hollow screw-gland 18 at the outer end of the coupling.

A second check-valve 19 may be employed to control the passage of lubricant from the duct 12 to a machine part to which the coupling is applied,`but this second valve is not positively essential in the operation of the gun and may be omitted.

Fitted for reciprocation in the piston chamber, is a piston 20, with which is associated a plunger 21 fitted for reciprocation Figure 2, an end view of the un, looking in the plunger-chamber.

A stufling box 22 at the end of the small cylinder 10, prevents leakage of lubricant @round the plunger into the larger cylinin the direction of the arrow A 1n Figure 1,

Figure 3, a section taken on the line 3 3, Figure 1,

Figure 4, a section along the line 4 4, Figure 1, and

Figure 5, an enlarged fragmentary section on the line 5 5, Figure 2.

Referring further to the drawing, the gun comprises a stock 5 provided with a curved i seat 6 for the support of the reservoir 7.

The stock carries the operative parts of connecting said parts with the reservoir, and

it is further associated with a source of' fluid under pressure, and with hand-controlled devices for connecting the source der 8.

A coiled spring 23 returns the connected pistons to the/ir normal position after each ejective movement., It will be apparent thatthe pressure pump thus produced operates.

on the principle of a hydro-static press to the extent that it involves an element having differentiated areas, one of which is subJect to the gun propertogether with means for. fluid pressure -for the exertion of a correspondingly multiplied pressure by the other. f At the'other end of the stock 5 is a socket 24 which, at its outer end, is provided with va packin with the grease-ejecting element of the gun. 26 on th gland 25, to admit another nipple e reservoir 7.

The socket is partitioned by a threaded plug 27 which defines a valve-chamber 28, and which provides a-valve-seat 29 in connection with a central passage 30.

A valve 31, of preferably spherical form, is mounted on a stem 32 which moves through the v'passage of the screw-plug.

The end of the stem, at the opposite end of the plug, has a head to be engaged by the end of the nipple 26, and a coiled spring 33 in the valve chamber, holds the valve to 'itsseat when the nipple is withdrawn from the socket.

The valve-chamber 28 is connected with the larger cylinder of the pump by a duct 34,

comprising a number of intercommunicat-- ing passages in the body of Elie stock. The passage of air or other pressu e fluid through this duct from the valve-chamber of the socket 24 to the piston-chamber 8, is nor-4 mally obstructed by a valve 35, which is held l in place against a Vvalve-seat 36 by a coiled spring 37. l

The valve has a stem provided with an exhaust valve 38. The exhaustv valve is engaged by a triggerv 39 pivoted on the stock, as at 40. f

Movement of the trigger 39 moves the valve 38 to its seat and moves thevalve 35'from its Seat, admitting fluid pressure in the duct 34 to the larger piston. When thel trigger is released, the spring 37 seats the valve 35 and opens thevalve 38, allowing the fluid pressure in the cylinder 8 to exhaust into the at mosphere.

The duct 34 has, at a pint between the socket and the valve-seat, a nipple 41, f or its connection with a sourceof pressure-fluld,

the connection being usually established by medium of a flexible conduit 42. The reservoir consists of a cylindrical containerfnormally supported upon the seat 6 of the stock. x

The container is closed at its 43 and 44, and these heads` carry the before mentioned nipples 26 and 15, which consist of short screw-threaded tubes tapered at their ends to facilitate their insertion through the pacllring glands 25 and 14, at the ends of the stoc A free floating piston 45., in the container,

divides the latterainto an air-chamber 46 and a lubricant-chamber 47.

When the container is iu'itsl operative position with relation to the pump-element, its nipples extend through the packing-glands to connect the air-chamber 46 and the lubricant-chamber 47, respectively` with the sockl.

et 24 and with Ythe coupling 13.

The container in th'isposition is fastened in place by two latch bars 48, which embrace the head at tlie lower edge'. thereof, as shown in Figure 2, and which are held in contact with the head by a toggle lever 49, an arm 50 of which engages with studs 51, at the ends ends by heads of the bars. The bars are slidably held in correspondingly formed slide ways at the rear end of the stock. y

In the operationv of the grease-gun, a reservoir whose lubricant-chamber 47 has previously been lsupplied with a lubricant, is fastened upon the seat'6 of the stock by means of the latch bars 48. In this position, the nipple on the head 43 of the reservoir, extends through the packing gland 25 into the socket 24 and the nipple 15, at the opposite end of the reservoir, extends through the packing` gland 14 into the hollow coupling-member 13 of the head 9 of the piston-cylinder 8 on the stock 5.

The nipple 26, by engagement with the stem 32, has separated the valve 31 from its seat, thereb establishing'a constantly open connection etween the source of pressurefluid and the air chamber 46 of the barrel.

The valve '35 normally engages its seat to obstruct the passage-of air from the source to the piston-chamber 8, ythrough the duct 34, and the large piston 20, and the therewith connected smaller piston 21, arey held at the ends of their respective chambers by the spring 23. i v

The valve 16, in the couplin normally held to its seat by the spring 17,v o structs the connection between the duct 12 andthe lul during a. preceding operation of the gun.

rl `he piston-chamber measures the quantity of lubricant that can, at one time, be fed to a machine partto which the gun is applied.

The gun, in its operative condition, is attached to the source of air under pressure, by the conduit 42, and it is held in the hand of the operator who inserts his fingers through finger-opening 52 of the'stock 5.

After the coupling-member 13 has been connected by any suitable means to the machine-part to be lubricated, the operator presses. against the trigger 39, which projects in one of the finger-openings, and thereby opens the valve 35 and closes the valve 38 in the duct 34; This establishes the communication between the source of pressure-Huid and the piston-chamber 8, with the result that the large piston 2O is driven forwardly against the resistance of the spring 23.

The Aplunger 21 moving in conjunction .with the larger piston, now drives a quantity of lubricant, measured by the content of the small piston-chamber, out from the duct 12 to the machine-part to which the couplingmember has been applied.

When the trigger 39 is released, the spring 37' closes the valve 35,`shutting off the supply of fluid pressure in the duct 34, and opens the valve 38, allowing the fiuid pressure in the cylinder 8 to exhaust into the atmosphere, and the spring 23 returns the piS- tons to their original position.

The void created in the small piston-'chamber, and the duct 12, by the discharge ofthe lubricant to the machine-part, is now filled by the passage of a corresponding portion of the contents ofthe lubricant-chamber of the container past the valve 16 int-o the coupling-member, it being apparent that the 1ubricant in the'container is constantly under pressure by the air admitted past the valve 31 and through the nipple 26, to the floating piston 45.

The gun is now again in condition for another operation and the operations may be repeated untilthe lubricant-chamber of the container is entirely exhausted. When this occurs the container is removed from the stock by loosening the latch bars 48, and withdrawing the ni ples froml their respective glands which o viously is easily accomplished by sliding the container rearwardly along its seat on the stock.

As soon as the container is demounted, the

, valve 31`is moved to its seat by the pressure of the spring 33, thereby preventing the escape of air. y

Another container, previously filled with lubricant, is now mounted on the stock to rel place the empty one, and the operator, by

keeping a number of 'illed containers in reserve, may thus continuously feed a lubrii cant to the parts of an automobile, or other machine, as long as his supply of containers lasts.

Having thus described my improved grease-gun, I desire it understood that var1- ations in the construction and arrangement of the essential elements and parts thereof may be resorted to without departing from the scope of the invention.

I claim 1.y A grease gun comprising a stock, a lubricant-ejecting element on the stock, a demountable container on the stock, a piston dividing the container int-o a lubricantchamber and a pressure-chamber, a valvecontrolled connection between the lubricant-` chamber and the ej'ecting means, and valvecontrolled means connecting the ejectionelement with a source of pressure-fluid and connecting the source ofkpressure and the pressure-chamber, the said connections .1n- Vclu'ding nipples on the container, 1n sliding 1 relation to the stock..`

2. A grease gun comprising a stock, a lubricant-ejecting element on the stock, a demountable container on the stock, a piston dividing the container into a lubricantchamber and a pressure-chamber, a valvecontrolled connection between the lubricantchamber and theejecting means, valve-controlled means `connecting the ejection-element with a source of ressure-.fluid and valved connecting means etween 'the source on the stock and nipples on the container, in

sliding relation to the packing glands.

3. A grease gun comprising a stock, a demountable container on the stock, a piston dividing the'container into a lubricant-chamber and a pressure-chamber, a lubricantejecting element, on the stock, including piston-chambers of different diameters, connected pistons in the chambers, a coupling member on the stock in valve-controlled connection with the smaller piston-chamber, means on the stock for connecting the'larger piston-chamber with a source of pressurefluid, including a hand-controlled valve, a valve-controlled socket connected with the source of pressure and nipples on the container for connecting its chambers with the coupling and with the socket, respectively.

4. A grease gun comprising a stock, a demountable container on the stock, a piston dividing the container into a lubricantchamber anda pressure-chamber, a lubricant-ejecting element on 4the stock, a coupling-member on thestock in valve-controlled connection with the ejecting-element, means on the stock for connecting the ejecti'ng-element with a source of pressure-fluid, including a hand-controlled valve, a` valvecontrolled socket, connected with the source of pressure, and nipples on the container for the connection of its chambers with the coupling and with the socket, respectively.

5. A grease gun comprisingoa stock, a dei means on the stock for connecting the ejecting-element with a source of pressure-fluid, including a hand-controlled valve, a valvecontrolled socket connected with the sourceof pressure, and nipples on the container for the connection of its chambers with the coupling and with the socket, respectively, the nipple cooperatingwith the socket, controlling the position of the respective valve to open the same when the container is in place on the stock.

6. A 'grease guncomprising a stock, a demountable container on the stock, a piston dividing .the container into a lubricantchamber anda pressure-chamber, a lubricant-e]ecting element on the stock, a coupling-member on the stock in valve-pontrolled connection with the ejecting-element, means on the' stock for connectingl un Y the escape of Huid from the socket, a trigger on the stock in operative relation to the rst mentioned valve, and nipples on the container for the connection of its chambers Vith the coupling and with the socket, respectively, the nipple cooperating with the socket, controlling the position of the respective valve to open the same when the container is in place on the stock.

7.*A grease gun comprisinga stock, ademountable container on the stock, a piston dividing the container into a lubricantchamber anda pressure-chamber, a lubricant-ejecting element on the stock in valve- :ontrolled connection with the lubricantchamber, means on the stock for its connection with a source of ressure-luid, including a passage to the e]ectingelement, and a when the container is slid into socket, a hand-moved valve controlling the passage, a spring-pressed valve normally'- closing the socket against the escape of pressure-Huid, and a nipple on the container connecting its pressure-chamber with the socket,

. and engaging the valve to hold-it olf its seat.

8. A grease gun comprising a stock, a removable grease container slidably mounted on the stock, a. piston in the container for driving grease therefrom, nipples on the container at opposite sides of the piston, means on the stock for feeding pressure fluid to one of the nipples, ,to drive the piston, and mechanism connected with the other nipple Yfor, receiving and expelling grease driven fromk the container.

9. A grease gun comprising a stock, a` removable grease container slidably mounted on the stock, a piston in the container for driving grease therefrom, nip les on the container pointing in the same rection and being at opposite sides of the piston, fittings on the stock into which the nipples are slid, sition on the stock, and, means on lthe stoc for feedin air-pressure to one litting and to receive an expel grease driven from the other fitting.

10. A grease gun comprising a stock, a removable grease-container thereon, the stock havin a connection with the container to feed air-pressure thereto, means to automatically close said connection, said means being -rendered operative by removal 'of the container, and mechanism for expelling grease y diven from thecontainer by the air pressure.

11. A grease gun com rising a stock, having a pressure line, a lu ricant-ejecting ele-l ment on the stock, a demountable container on the stock the stock being' outside of the container, movable means dividing the container into a lubricant chamber and a pressure chamber, -a sliding connection between the lubricant chamber` and the ejecting means, and asliding connection between the pressure line and the pressure chamber.

12. A grease gun eomprisin a grease oontainer having an air inlet an a grease out- 4 let, a stock outside the container, and slid- 0' connections between the Istock and said in et and outlet.

13. A grease gun comprising a stock, a' grease container` on the stock, the stock be- 'ing outside the container, the container hav- In testimony whereofy I have aflixed my signature. CHARLES F. GODDARD. 

